backup light switch

[ruddyboys]

Have a common problem, no back-up lights. Seems my problem lies in the wiring. the switch has two wires hanging. I know one grey and brown wire goes to the back-up light and the second should go to the relay box. On the other side of the relay box should be a blue wire. I have a blue cut wire next to a green and white cut wire comming from the same harness that the coil and oil pressure switch wire comes from. I think the green and white wire is for the blower fan and the blue should be for the back-up lights. Problem is with key on no juice. I also have a blue wire comming from a harness were the relay box should be. Which wire do I use.

[philinjax]

There is no blue wire associated with the back up light switch. The two wires going to the switch are both GY/BR. The power to the switch comes from fuse S9. With the key on you should have 12 volts on one of the two GY/BR wires coming out of the back up light switch on the transmission case. When you select reverse with the gear shift, the back up light switch is activated by an internal pin from the transmission. Usually, the problem with no back up lights has to do with a defective switch. In fact, most back up light switches are defective or the pin that activates the switch gets worn down so that it will no longer trigger the switch. I replace the pins with new ones I fabricate from, I think, 11/64 inch drill bits.
Good luck with it,
Phil